[Objective] To study the inter-allelic recombination event occurring in the HLA-B locus, and to evaluate the molecular genetic mechanisms of a novel HLA allele, predict and analyze the impact of its amino acid residue changes on the three-dimensional structure. [Methods] HLA typing was taken with polymerase chain reaction-sequence specific oligonucleotide probes (PCR-SSOP) by Luminex. Sequence-based typing (SBT) and gene clone were used to analyze exons 1-4 sequences of HLA-B allele. In order to determine the exact site of inter-allelic recombination event occurring in the HLA-B locus, sequences of the HLA-B alleles were compared with the IMGT/HLA database by the program “Alignment”. After homology modeling using the Swiss-Model software, the three-dimensional structure of the molecules was simulated using the Swiss Pdb Viewer software, and the FATCAT online software was used to compare the differences in the three-dimensional structures of the molecules. [Results] HLA typing indicated the PCR-SSOP pattern did not match with any known HLA-B alleles, suspected to be a new HLA allele. The genetic clone sequencing results showed HLA-B alleles of the proband were B^*13∶02 and a novel allele. The HLA-B exon2 nucleotide sequence of the novel allele was different from any other known alleles. The novel allele has 12 nucleotides replaced when compared with the closest matching B^*35∶01∶01∶01 allele from c.259 to c.299, which result in 8 amino acids changes. The sequence was identical in B^*35∶01∶01∶01 in exon 1, exon 3, exon 4, intron 1, intron 2, intron 3 and at c.74 to c.258 in exon 2, and c.259 to c.343 sequence in exon 2 was identical in B^*46∶01∶01 by blast search. The structure of the mutant alleles was similar to that of B^*35∶01∶01∶01 and B^*46∶01∶01, and the local hydrogen bonds of amino acids p.63-p.79 were changed at the recombination site. [Conclusion] This study demonstrates a rare inter-allelic recombination event occurring in the HLA-B locus. It has been officially designated as HLA-B^*35∶186 by WHO Nomenclature Committee for Factors of the HLA System. It illustrates the process of novel allele, and provides new evidence for the further studying mechanisms of gene recombination and HLA polymorphism.

Objective To investigate the effect of a small amount of leukocyte mixed in platelets on platelet RNA relat-ed study,and to further propose a method to remove leukocyte contamination.Methods The collected platelets were divid-ed into groups and then processed.1)Control group:Cells were collected by direct centrifugation;2)Centrifuge purifica-tion group:Centrifuge with different centrifugal forces to collect precipitated cells and recover suspended cells;3)Magnetic bead purification group:Remove CD45 positive leukocyte from platelets using magnetic bead method,and recover CD45 negative platelet cells.Total RNA was extracted from the cells,and cDNA was reverse transcribed from the extracted RNA.The fragments of housekeeping gene β-actin,platelet marker ITGA2B and leukocyte marker PTPRC were PCR amplified u-sing cDNA as a template.The results of the PCR amplification were used to determine the influence of leukocyte contamina-tion in platelet mRNA study and the effect of centrifugation purification and magnetic bead purification.Results PTPRC gene could be detected in cDNA from platelet cells obtained by direct centrifugation.PTPRC gene was also detected in cell segments collected from both precipitated and suspended cells after centrifugation under different conditions.But PTPRC was not detected in platelet after removal of CD45 positive cells by magnetic bead.Conclusion A small amount of leukocyte contamination in platelets can interfere with the mRNA study of platelets.The simple centrifugation could not remove the leukocyte contamination in platelets,but the magnetic bead had a better purification effect.

Objective:To explore the impact of different referral timing on postponing early-onset pre-eclampsia (PE), postponing severe pre-eclampsia (SPE), reducing SPE severe complications and improving maternal and neonatal outcomes by analyzing the pregnancy outcomes of SPE patients who were referred from primary hospitals to tertiary referral center in the referral system.Methods:The clinical data of 159 SPE patients who were referred from primary hospitals, treated and then terminated their pregnancy in Peking University Third Hospital from January 2020 to October 2021, were observed and analyzed in this clinical observational study. According to the clinical stage of PE at the time of referral, they were divided into four groups: 38 cases were referred after onset of SPE severe complications (SPE-C group), 72 cases were referred after onset of SPE (a-SPE group), 15 cases were referred after onset of PE (a-PE group) and 34 cases were referred after detection of PE early warning-signs (Warn-s group). And then these 159 cases were divided into different color groups according to the project management system for high-risk pregnant women. Patients of Red color (highest risk) and Orange color (higher risk) were required to be referred to tertiary hospitals (Red-Orange group, 113 cases), and patients of Yellow color (high risk) could be treated under tertiary hospitals (Yellow group, 46 cases). The maternal and neonatal outcomes of different referral timings were analyzed and compared.Results:(1) Pregnancy outcomes of different referral timings grouped by PE clinical stage at the time of referral: the later the referral timing, the higher the rate of SPE severe complications, the shorter the interval from referral to termination of pregnancy. The rate of SPE severe complications in the SPE-C group was significantly higher than those of the other three groups, and the interval from referral to termination of pregnancy in the SPE-C group was significantly shorter than those of the other three groups (all P<0.05). The referral gestational age of Warn-s group was earlier than those of the other three groups (all P<0.05). The average gestational ages for onset of SPE, termination of pregnancy, and onset of SPE severe complications were all after 34 gestational weeks, and were later than those of a-SPE group and SPE-C group; the rates of SPE onset before 34 gestational weeks, SPE severe complications onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, neonatal intensive care unit (NICU) hospitalization, and pregnancy giving up before 28 gestational weeks were lower than those of a-SPE group and SPE-C group, the length of NICU stay was shorter than those of a-SPE group and SPE-C group, and its rate of take-home-babies was 100%, significantly higher than those in a-SPE group and SPE-C group (all P<0.05). The gestational ages for onset of SPE and termination of pregnancy in a-PE group were later than those in a-SPE group and SPE-C group, the rates of SPE onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, and NICU hospitalization were lower than those of a-SPE group and SPE-C group, the length of NICU stay was shorter than those of a-SPE group and SPE-C group (all P<0.05). (2) Pregnancy outcomes of different referral timings grouped by the color classification of PE clinical characteristics: among the 159 cases of SPE, 113 cases (71.1%, 113/159) were in the Red-Orange group which were required to be referred to tertiary hospitals, and 46 cases (28.9%, 46/159) were in the Yellow group,which were not in the range of referral requirements, but actually referred to the tertiary hospital and eventually developed SPE. Gestational ages for onset of SPE, termination of pregnancy, and onset of SPE severe complications in the Yellow group were later than those of the Red-Orange group, while the rates of SPE onset before 34 gestational weeks, SPE severe complications onset before 34 gestational weeks, terminating pregnancy before 34 gestational weeks, NICU hospitalization, and pregnancy giving up before 28 gestational weeks were lower than those of the Red-Orange group, the length of NICU stay was shorter than that of the Red-Orange group, and its rate of take-home-babies was higher than that in the Red-Orange group (all P<0.05). (3) Analysis of different clinical referral timings in the Yellow group: among these 159 SPE patients, 46 cases (28.9%, 46/159) would be excluded from the range of referral requirements which belonged to the Yellow color grade, but 6 cases still developed SPE severe complications (4 cases in Warn-s group and 2 cases in a-PE group), 17 cases were terminated pregnancy before 34 weeks of gestation (12 cases in Warn-s group and 5 cases in a-PE group), and 23 cases developed SPE before 34 weeks of gestation (17 cases in Warn-s group and 6 cases in a-PE group). (4) Multivariate analysis: referral after detection of PE early warning signs was the independent protective factor for postponing the onset of SPE severe complications ( P<0.05). Referral after detection of PE early warning signs and referral after onset of PE were both protective factors for postponing the onset of SPE and early-onset PE (all P<0.05). Conclusions:Different referral timing in the referral system is one of the key points that affect the maternal and neonatal outcomes of SPE. Referral after detection of PE early warning signs and timely referral after onset of PE would reduce early-onset PE, postpone the onset of SPE and reduce the severe complications of SPE. The clinical development and evolution of PE is really complicated, and referral based on specific clinical situations is better than referral based on fixed mode.

China/epidemiology* ; Humans ; Pemphigoid, Bullous/epidemiology* ; Retrospective Studies

【Objective】 To study the correlation between type ⅡCD36 deficiency and the polymorphism of intron sequence. 【Methods】 A total of 516 random healthy platelet donors from Liaoning Blood Center were involved: 241 of them were tested for CD36 antigen and CD36 gene sequence; the remaining 275 cases were sequenced only. CD36 antigen was detected by flow cytometry, and gene sequence was analyzed by PCRamplification and sequencing. 【Results】 Among the 241 samples, 1 case of type Ⅰ deficiency and 4 cases of type Ⅱ deficiency were detected, with frequencies of 0.41% and 1.66%, respectively. There was no nucleotide change in the coding region of 3 cases of typeⅡdeficiency. All individuals with type Ⅱ deficiency shared a common polymorphism in the intron 3, that is, carried (TG) 11 and 12 linked variants, and both were located in the same allele. The gene frequency of (TG)11 in the 516 random population was only 11.72%, which was much lower than 30.43% of (TG)13. The gene frequency of 12 linked variants in the random population was 8.81%. Almost all 12 linked variants occurred simultaneously with (TG)11, but only about 72.7% of (TG)11 were tandem with 12 linked variants. Flow cytometry showed that the expression of CD36 antigen on platelet in samples carrying only (TG)11 was comparable to that of normal samples, while the vast majority of samples carrying both (TG)11 and 12 linked variants had significantly lower CD36 antigen levels. 【Conclusion】 The (TG)11 in the intron 3 region is not platelet-specific silent allele, but there are some indirect correlations. There may be multiple platelet-specific silent allele.

OBJECTIVE: To study rare para-Bombay blood type Bm METHODS: ABO and H phenotype of the proband and her pedigree were determined with serological methods. The ABO genotype was analyzed by polymerase chain reaction-sequence specific primer(PCR-SSP). The full coding region of alpha-l,2 fucosyltransferase (FUT1) gene of the pedigree was analyzed by polymerase chain reaction and direct sequencing of the amplified fragments. The haplotype of the FUT1 gene were analyzed by cloning sequencing. RESULTS: The rare para-Bombay blood type Bm CONCLUSION Two new alleles of FUT1 gene (h
ABO Blood-Group System/genetics* ; China ; Female ; Fucosyltransferases/genetics* ; Genotype ; Humans ; Phenotype

Objective:To investigate the status quo of human resources of dentists who deal with periodontal disease in Beijing area through an online survey, which may hopefully provide a preliminary basis for the decision-making of administrative departments and the formulation of periodontal professional development plan.Methods:The dentists who deal with periodontal disease at least half a day per week in Beijing area were investigated. A questionnaire was designed by the chairman of the Periodontology Committee of Beijing Stomatological Association. The questionnaire was sent to and finished by the dentists via "WenJuanXing" online survey software. The contents of the survey included general condition, the property of practice unit, title and position of the dentist, membership of professional society, time and content of periodontal treatment, adoption of new technology and new method of periodontal therapy during the past one year, status of periodontal treatment in the local population and reasons, understanding and influencing factors of periodontal professional development.Results:A total of 1 255 dentists completed the survey, who came from all 16 districts in Beijing, mainly Haidian, Chaoyang, Dongcheng and Xicheng Districts [The total percentage of these four main districts was 70.3% (882/1 255)]. The mean age of the dentists was (36.1±8.3) years. Among the dentists, 71.1% (892/1 255) were females, 88.1% (1 106/1 255) got a Bachelor′s degree or above. It was estimated that 35.4% (444/1 255) of the dentists had received standardized periodontal training ever. The percentage of dentists carrying out new technology in the past one year was as high as 68.1% (855/1 255). There were only 163 periodontal specialists (13.0%) out of the dentists in the survey. Only 15.9% (200/1 255) of the dentists routinely performed periodontal surgery. The majority of the dentists [82.8% (1 039/1 255)] were from the state-owned hospitals. Fifty-four point seven percemt (686/1 255) of the dentists thought that lack of knowledge was the main reason why the general public failed to receive periodontal treatment. As for the biggest bottleneck affecting periodontal professional development, fifty-one point zero percent (640/1 255) of the dentists attributed it to the public neglect.Conclusions:The periodontal practitioners in Beijing are young, highly educated, unevenly distributed in 16 districts and mostly females. State-owned oral health institutions are an important force in periodontal diagnosis and treatment services in Beijing. The number of periodontal specialists need to be improved. Promotion of standardized periodontal surgery and the popularization of healthcare knowledge on periodontal disease should also be the focus in the future.

OBJECTIVETo explore the molecular mechanism for a case with para-Bombay phenotype caused by α-1,2-fucosyltransferase (FUT1) gene mutations.

METHODSBlood phenotype of the propositus was determined by standard serological testing. Polymerase chain reaction-sequence specific primer (PCR-SSP) and direct sequencing of PCR product were used to analyze its ABO genotype. The PCR product of FUT1 gene was sequenced and analyzed.

RESULTSThe phenotype of the propositus was initially detected as para-Bombay A type. Direct sequencing of ABO gene showed that the genotype of the proband was A101/O01 (261G/del), which was consistent with the result of PCR-SSP. Two homo-mutations, 35C>T and 658C>T, were detected in the FUT1 gene by sequencing, and the genotype was determined as h(35T+658T)/h(35T+658T).

CONCLUSIONh(35T+658T)/h(35T+658T) is responsible for the para-Bombay phenotype of the propositus. The genotype is rare even in para-Bombay populations.

ABO Blood-Group System ; genetics ; Base Sequence ; DNA Mutational Analysis ; methods ; DNA Primers ; Fucosyltransferases ; genetics ; Genotype ; Homozygote ; Humans ; Male ; Phenotype ; Point Mutation ; Polymerase Chain Reaction

BACKGROUND:As a main antigen of platelet, CD36 antigen is also known as platelet glycoprotein IV (GPIV). The mutation of CD36 gene may result in deficiency of the antigen.
OBJECTIVE:To identify a novel CD36 alele.
METHODS: DNA was isolated from peripheral blood sample, and 12 coding regions of CD36 gene were amplified by PCR. Sequencing-based typing was used to analyze the sequence of the target regions. The derived sequences were aligned with the standard sequence of NG_008192 in GenBank to identify the novel alele.
RESULTS AND CONCLUSION: 1142 T>G mutation was detected in exon 12 of CD36 gene of the proband, and the other regions were consistent with the standard sequence. No data or report about 1142 T>G was found in GenBank or National Center for Biotechnology Information (NCBI), and thus it was reported to GenBank and received by number KM275213. 1142 T>G results in amino acid 381 Leu>Ser of the CD36 protein. There is a big difference in hydrophilia and polarity of the two amino acids. Also the 381 amino acid locates in highly conserved region. Thus it is speculated that 1142 T>G may reduce or vanish the activity of the protein.

OBJECTIVETo explore the molecular basis for an individual with a rare weak D phenotype.

METHODSSerological methods were used to characterize the RhD blood group phenotype. The exons of RHD gene were amplified with PCR and sequenced. The presence of Rhesus box was tested by PCR to determine the homozygosity of RHD gene.

RESULTSThe RhD blood group of the proband was detected as weak D. The 10 exons of the RHD gene and Rhesus box could be amplified by PCR, and the genotype of RHD alleles was determined as RHD+/RHD-. The exons of the RHD gene were sequenced, and a 365C>T mutation in exon 3 was detected. Therefore, the RhD blood group of the proband was confirmed as weak D type 54 by both serological methods and DNA sequencing.

CONCLUSIONA weak D type 54 has been detected. A 365C>T mutation in RHD gene is responsible for the low expression of D antigen.

Alleles ; Base Sequence ; Exons ; Genotype ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Phenotype ; Point Mutation ; Rh-Hr Blood-Group System ; genetics